Remote catalyzation for direct formation of graphene layers on oxides.
Remote catalyzation for direct formation of graphene layers on oxides.
复制标题
DOI：
10.1021/nl204024k
复制
发表时间：
2012-02
期刊：
影响因子：
10.8
通讯作者：
Po-Yuan Teng;Chun-Chieh Lu;Kotone Akiyama-Hasegawa;Yung‐Chang Lin;C. Yeh;K. Suenaga;P. Chiu
中科院分区：
文献类型：
--
作者：
Po-Yuan Teng;Chun-Chieh Lu;Kotone Akiyama-Hasegawa;Yung‐Chang Lin;C. Yeh;K. Suenaga;P. Chiu
在绝缘基底（如SiO（2））上直接沉积高质量的石墨烯层为石墨烯基高速电子产品的发展铺平了道路。在这里，我们描述了一种新的生长技术，该技术能够在SiO（2）上直接沉积石墨烯层，其结晶质量可能与使用化学气相沉积（CVD）在Cu箔上生长的石墨烯相当。我们的方法不是使用铜箔作为衬底，而是使用它们在CVD工艺中提供升华的Cu原子。所提出的技术的主要特点是远程催化使用浮动的铜和氢原子的烃类的分解。这允许碳自由基在氧化物表面上的直接石墨化，形成隔离的低缺陷石墨烯层，而不需要金属催化剂的生长后蚀刻或蒸发。通过调整生长参数，如气体比例、Cu表面积和衬底到Cu的距离，可以显著降低所得石墨烯层的缺陷密度。在优化的条件下，当使用预沉积的石墨片作为种子用于扩展生长时，可以获得具有不可辨别的拉曼D峰的石墨烯层。
Direct deposition of high-quality graphene layers on insulating substrates such as SiO(2) paves the way toward the development of graphene-based high-speed electronics. Here, we describe a novel growth technique that enables the direct deposition of graphene layers on SiO(2) with crystalline quality potentially comparable to graphene grown on Cu foils using chemical vapor deposition (CVD). Rather than using Cu foils as substrates, our approach uses them to provide subliming Cu atoms in the CVD process. The prime feature of the proposed technique is remote catalyzation using floating Cu and H atoms for the decomposition of hydrocarbons. This allows for the direct graphitization of carbon radicals on oxide surfaces, forming isolated low-defect graphene layers without the need for postgrowth etching or evaporation of the metal catalyst. The defect density of the resulting graphene layers can be significantly reduced by tuning growth parameters such as the gas ratios, Cu surface areas, and substrate-to-Cu distance. Under optimized conditions, graphene layers with nondiscernible Raman D peaks can be obtained when predeposited graphite flakes are used as seeds for extended growth.